Established 2004

Ruddlesden geotechnical

Ruddlesden geotechnical provides ground investigation, geotechnical consultancy and contamination assessment services.

Based in Exeter, but covering the whole of the UK, albeit primarily concentrated in the South West, Ruddlesden geotechnical was formed in 2004.

Ruddlesden geotechnical works on behalf of a wide client base, including local, regional and national housing developers, housing associations, commercial developers, building contractors, structural and civil engineers, architects, building consultants, quantity surveyors, local authorities and private individuals.

Development projects range from single dwellings and extensions to large housing estates, multi-storey flats, offices, industrial units, roads, slopes, schools, hospitals and basements.

The services and projects listed on this web-site provide an indication of those undertaken by Ruddlesden geotechnical, but others are carried out. If your requirement is not readily identifiable on this web-site, please contact us as we may still be able to help you.

  • AGS
  • Constructionline
  • CSCS
  • SMAS
  • ECFC trust
  • Latest news

    13 Jul 2026

    Geoff’s birthday treats!

    We recently celebrated a special birthday of Geoff Davis, in a place that is close to his heart: the East Devon coast.He treated us to his knowledge of the geology and landslide systems in the area, and we treated him to an ice cream on the beach!

    Geoff’s birthday treats!
    Geoff’s birthday treats!
  • Recent projects

    Bioaccessibility Testing Negates Remediation

    The chemical laboratory test results obtained as part of a Phase 2 contamination investigation for a proposed residential development in South Devon indicated elevated levels of arsenic to be present in natural soils. A generic qualitative risk assessment (GQRA) showed that all the recorded levels of arsenic exceeded the generic assessment criteria (GAC), indicating that remediation or further assessment was required. Based on the conceptual site model (CSM), as no significantly elevated levels of contamination were expected, but given the underlying geology naturally elevated levels of metals and metalloids may be present, it was considered that further assessment should be undertaken instead of remediation. A detailed quantitative risk assessment (DQRA) was therefore carried out, including additional bioaccessibilitytesting, as the GAC to which the recorded levels of arsenic were initially compared assumes that 100% of the arsenic is bioaccessible, whereas naturally occurring elements are typically not 100% bioaccessible. The bioaccessibility test is a laboratory test that simulates conditions in the gastrointestinal tract to assess the human bioaccessibility of potentially harmful elements by ingestion. As the ingestion pathway is the primary migration pathway for arsenic, the bioaccessibility significantly affects the assessment criteria. The results of the bioaccessibility testing were incorporated into the CLEA, in which the end users were also modified, as the proposed development was for a residential care home rather than a standard residential land use, to produce a site-specific assessment criterion, which was greater than all of the recorded levels of arsenic. It was therefore concluded that the recorded levels of arsenic were not likely to be harmful to end users, given the proposed end use, and that no remediation was necessary. Carrying out this further testing and detailed quantitative risk assessment (DQRA) avoided the need to carry out unnecessary remediation.

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  • Recent projects

    Sand Replacement Testing Undertaken to Validate Earthworks, Torbay

    Following the production of an earthworks specification, Ruddlesden geotechnical undertook in-situ sand replacement testing, to confirm the dry density of compacted material, and collected representative samples for geotechnical laboratory testing, to confirm the moisture content and suitability of the compacted material, to validate the deposition of materials during the construction of an embankment. The embankment was being constructed as part of a larger earthworks scheme, which formed the enabling works for a residential development in Paignton. Liaison with the groundworkers and client was key to the success of the earthworks. Delays in material placement, particularly during periods of inclement weather, can lead to excessive time delays and hence additional costs.

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